Most interesting US approaches:

- DCA River Visual
- VOR 13 at JFK
- Expressway visual at LGA
- Aspen (ASE)
- Fast and Furious at ORD (anything on any given day)

I am sure there are others.

The wildest ones in Europe I used to fly were in LCY, LUG and BRN. Lugano (LUG) was the craziest, with a 6.67 degree glideslope to be left downwards to intercept the 4.0 degree visual part of the approach. Draw a picture and do the math. Pucker factor there is high too.